UPDATE 4-Holiday promotions to hurt MetroPCS, shares dive

* Rate plan changes, Q4 promotions pressure ARPU - CFO

* MetroPCS not talking to Leap; not considering sale

* Q3 EPS $0.21 vs est $0.09; Q3 rev beats estimates

* Cuts subscriber, EBITDA forecasts for 2009

* Shares sink more than 14 pct to all-time low (Adds CEO comments from interview)

By S. John Tilak

BANGALORE, Nov 5 (Reuters) - MetroPCS Communications Inc's (PCS.N) warning that holiday season promotions could hurt the revenue it gets for each subscriber sent shares plunging to an all-time low, showing that intensifying competition continues to peg back the low-cost wireless carrier.

The fierce dogfight in the cheap unlimited wireless prepaid services sector, as larger carriers show interest in what was once the domain of MetroPCS and rival Leap Wireless (LEAP.O), has led to chatter that the company could be considering selling itself.

But CEO Roger Linquist downplayed the M&A talk.

MetroPCS was not considering the option of selling itself, nor was it in talks with Leap, Linquist told Reuters in an interview.

"We're not currently pursuing them," Linquist said. Companies like America Movil (AMXL.MX)(AMX.N), AT&T (T.N) or Deutsche Telekom's (DTEGn.DE) T-Mobile USA have been seen as possible acquirers by analysts.

When asked if MetroPCS was approached by companies interested in buying the carrier, Linquist said: "I wouldn't comment on that anyway, but I'd say no."

MetroPCS shares reversed course after opening up 4 percent as investors continued to punish the stock, which has shed 45 percent since it last reported quarterly results in August.

"The rate plan changes we made in August and fourth-quarter promotions will result in downward pressure in average revenue per user (ARPU) over time," Chief Financial Officer Braxton Carter said on a conference call.

In the interview, Linquist said ARPU could be hurt in the fourth quarter and further in 2010.

Earlier, the low-cost wireless carrier reported quarterly earnings and revenue above market estimates as average revenue per user rose in the third quarter.